Longitudinal cutting machine with a cooled cutter blade

ABSTRACT

A longitudinal cutting machine for cutting a sheet of material conveyed through the cutting machine, comprising a cutter arrangement, provided with at least an upper cutter, for the sheet of material, which is conveyed through the cutter arrangement across the cutting point formed by the upper cutter, and at least one nozzle for conveying cooling medium onto a cutter blade of the upper cutter, wherein the nozzle extends or is distributed over a periphery or length of the cutter blade.

The invention relates to a longitudinal cutting machine for cutting asheet of material that is conveyed through the longitudinal cuttingmachine, and includes a cutter arrangement, which is provided with atleast one upper cutter, for the sheet of material, which is conveyedthrough the cutter arrangement across a cutting point formed by theupper cutter.

A longitudinal cutting machine having the aforementioned features isknown from U.S. Pat. No. 3,185,010. With such longitudinal cuttingmachines, applications occur in connection with which the material thatis to be cut adversely affects the cutting process to a greater orlesser degree as a function of the atmospheric temperature. Thus, forexample, when cutting sheets of material that are coated with anadhesive, material residue frequently adheres to the blades, wherebyalso the temperature that rises at the cutting point due to the cuttingfriction can adversely affect the cutting result, which is particularlyapplicable to the high cutting speeds that are desired.

It is therefore an object of the present invention to provide alongitudinal cutting machine having the aforementioned features thatenables a better cutting result for temperature sensitive materials,even at high cutting speeds.

The realization of this object, including advantageous embodiments andfurther developments of the invention, results from the content of thepatent claims that follow this description.

The basic concept of the invention is that cooling medium can besupplied to the cutter blade of the upper cutter via at least one nozzlethat is directed onto the upper cutter in such a way that during thecutting operation of the longitudinal cutting machine, the temperatureof the cutter blade does not exceed a prescribed temperature.

Thus, for a longitudinal cutting machine, the invention is directed tocooling the cutter blade of the upper cutter by supplying it with asuitable cooling material, i.e. is directed to keeping the temperatureof the cutter blade below a set temperature, even during the cuttingprocess, so that even at very high cutting speeds, at which one canexpect an increased heating of the sheet of material that is to be cutat the cutting point, adherence of substituents of the cut sheet ofmaterial on the cutter blade is prevented. Since only the cutter bladehas to be kept cool, the energy consumption is also kept withinappropriate limits. To the extent that nozzles are provided for theapplication of the cooling medium, such nozzles do not primarily providea precise concentrated stream, but rather supply at least a laminarportion of the cutter blade that adjoins the cutting edge of the blade,for which purpose the corresponding nozzles can, for example, have aslotted discharge for the cooling medium.

Pursuant to one embodiment of the invention, a plurality of nozzles areprovided that are distributed over the periphery of the circular cutterblade and are directed onto the cutter blade; alternatively, a singlenozzle, embodied as a slotted nozzle, can extend over the periphery ofthe circular cutter blade.

In addition to embodying the upper cutter as a circular cutter, it isalso conceivable to embody the cutter as a longitudinal cutter, and tothis extent, pursuant to one embodiment of the invention, the cutter isembodied as a longitudinal cutter and is provided with a plurality ofspaced-apart nozzles that are disposed over the length of the cuttingedge of the longitudinal blade; alternatively, it is also possible toembody the cutter as a longitudinal cutter and to provide a singleslotted nozzle that extends over the length of the cutting edge of thecutter blade.

Pursuant to one embodiment of the invention, the nozzle for the coolingmedium that is to be conveyed therethrough is directed onto the innerside or edge of the cutter blade that during a shearing cut restsagainst the lower cutter; since in particular in this cutting region theoccurrence of adherence of the sheet of material is most likely, herethe invention is applied by cooling the inner side of the cutter blade.

Pursuant to one embodiment of the invention, the cutter blade of theupper cutter can be supplied with the cooling medium by nozzles disposedon both sides of the blade. Alternatively, or in addition thereto,especially the cutting edges of the blade can be cooled, for whichpurpose, pursuant to one embodiment of the invention, at least onenozzle is directed onto the cutting edge of the blade in a radialdirection relative to the cutter blade.

Pursuant to one embodiment of the invention, where several cutter bladesare slightly spaced from one another, a nozzle arrangement for supplyinga plurality of cutter blades is provided. Such an arrangement isparticularly suitable for very narrow cutting widths.

Pursuant to embodiments of the invention, a constant stream of coolingmedium can be conveyed through the nozzles, or the nozzles are suppliedwith the cooling medium at periodic intervals.

To supplement the blades that are to be kept appropriately cool,pursuant to one embodiment of the invention, the sheet of material canbe cooled at the cutting point itself by a nozzle that is orienteddirectly onto the cutting point.

Pursuant to one embodiment of the invention, the upper cutter, includingthe nozzle that is directed onto the cutter blade thereof, is surroundedby a housing, whereby a vacuum device for the cooling medium that isapplied can be connected to the housing. To the extent that with analready addressed embodiment of the invention slightly spaced apartcutter blades are provided, the housing, along with a pertaining nozzlearrangement, can appropriately enclose a plurality of cutter blades.

With regard to the control of the use of the cooling medium, atemperature sensor can be associated with the cutter blade to detect therespective temperature of the upper cutter.

At least one nozzle can be oriented onto the sheet of material in thatregion thereof that is disposed upstream of where the sheet passesthrough the cutting point, so that as a supplement to the cooling of thecutter blade, the temperature of the sheet of material prior to entryinto the cutter arrangement can also be lowered.

Pursuant to a particular embodiment of the invention, at least onenozzle can be directed onto that region of the already cut sheet ofmaterial that is disposed downstream of the cutting point and includesthe cut edge in the sheet of material. To the extent that during astandstill of the longitudinal cutting machine the cut edges of theportions of the sheet of material that have just been separated by thecutter arrangement can again stick together, a cooling of the sheet ofmaterial that is also effected downstream of the cutter arrangement asviewed in the direction of transport of the sheet of material effects acertain embrittlement, so that when the sheet of material again startsto run, the cut portions of the sheet of material automatically separatefrom one another.

Pursuant to one embodiment of the invention, the lower cutter that isassociated with the upper cutter is embodied as a lower cutter shafthaving cutting edges disposed thereon, and the lower cutter shaft isdesigned for conveying the cooling medium therethrough.

The invention is also suitable for cutter arrangements that operate in acrimping cut mode, and to the extent that in this connection the uppercutter operates against a shaft, in addition to the cooling of the uppercutter the shaft can also be designed for conveying the cooling medium.

Pursuant to embodiments of the invention, the cooling medium can becooled air, an inert cooling gas, a liquid nitrogen or also a liquidcarbon dioxide; further suitable media can also be used within the scopeof the invention.

To the extent that the embodiment of the upper cutter and/or lowercutter of metal also make possible an electrical cooling, pursuant toone embodiment of the invention the cooling device can also provide anelectrical cooling of the upper cutter and/or lower cutter.

Embodiments of the invention will be described subsequently with the aidof the drawings, in which:

FIG. 1 shows a cutter arrangement comprising an upper cutter, which issupported on a cutter holder and is embodied as a circular cutter, andan associated lower cutter, with a cooling nozzle,

FIG. 2 shows the cutter arrangement of FIG. 1 with a plurality ofindividual nozzles and a single annular slotted nozzle,

FIG. 3 shows another embodiment of a cutter arrangement having uppercutters, including associated cooling nozzles, disposed on a cuttershaft,

FIG. 4 shows the cutter arrangement of FIG. 1 with an additional coolingregion for the sheet of material disposed prior to its passing throughthe cutter arrangement,

FIG. 5 shows the cutter arrangement of FIG. 1 with an additional coolingregion for the sheet of material downstream of where it passes throughthe cutter arrangement,

FIG. 6 shows a longitudinal cutter, with cooling nozzles, suitable for acutter arrangement,

FIG. 7 shows a further embodiment of the cutter arrangement of FIG. 1with a radially disposed nozzle and a housing having a vacuum device.

As can be initially seen from FIG. 1, supported on a blade or cutterholder 10 by means of a lowering mechanism 11 is an upper blade orcutter that is embodied as a circular cutter 12 and that is surroundedby a hand guard 13. Associated with the cutter blade 14 of the circularcutter 12 is a lower blade or cutter 15 in such a way that a cuttingpoint 16 results though which a web or sheet of material 17 is guided inthe direction of transport indicated by the arrow 18. Slightly upstreamof the cutting point 16 as viewed in the direction of transport, anozzle 19 is directed onto the cutter blade 14 in order, by passing asuitable cooling medium through the nozzle 19, to cool the cutter blade14 before the associated cutting edge of the blade respectively reachesthe cutting point 16 and hence comes into contact with the sheet ofmaterial 17. It is to be understood that the nozzle must respectively bedisposed ahead of the cutting point 16 as viewed in the direction oftransport of the sheet of material 17 through the cutter arrangement. Ascan be seen from the sketch of FIG. 1 a, it would also be possible todispose appropriate nozzles on both sides of the cutter blade 14 forconveying cooling medium thereto, so that, as indicated by the arrows30, an appropriate cooling medium can be directed onto both sides of thecutter blade 14.

As shown in FIG. 2, a plurality of nozzles 19 can be distributed overthe periphery of the cutter blade 14. In FIG. 2, to facilitateillustration, a further alternative is shown, according to which,instead of the individual nozzles 19, a circumferentially extendingannular slotted nozzle 20 is provided, so that the entire periphery ofthe cutter blade 14 can receive the cooling medium stream via theannular slotted nozzle 20.

FIG. 3 illustrates a further embodiment of the invention, according towhich a plurality of circular cutters 12, as the upper cutter, aredisposed on a common cutter shaft 23 and in a shearing cut operateagainst the lower cutter 15, which has correspondingly associated bladecutting edges, whereby a respective nozzle 19 is associated with each ofthe circular cutters 12 in that region thereof that is disposed oppositethe cutting point 16.

As can be seen from FIG. 4, an additional cooling of the sheet ofmaterial 17 can be effected ahead of the cutting point 16, as viewed inthe direction of transport 18 of the sheet of material 17, by disposinga cooling bar 21 having a plurality of cooling nozzles 22 disposedtherein parallel to the upper surface of the sheet of material 17. Withthis embodiment, in addition to the cooling of the cutter 12 that isstill retained, a cooling of the sheet of material 17 is effected.

Pursuant to the embodiment of the invention illustrated in FIG. 5, acooling bar 21 having appropriately associated cooling nozzles 22extends behind or downstream of the cutting point 16, as viewed in thedirection of transport 18 of the sheet of material 17, and is orientedparallel to the sheet of material 17. In this way, that region of thesheet of material 17 that includes the cut edge that has already beencut in the sheet of material 17 is cooled, thus achieving in aparticularly advantageous manner a certain embrittlement of the sheet ofmaterial 17 by cooling the sheet of material downstream of the cuttingpoint 16, so that after a possible standstill of the longitudinalcutting machine, when the sheet of material again starts running the cutportions of the sheet of material automatically separate from oneanother.

A further embodiment of the invention is shown in FIG. 6, according towhich the blade that is to be cooled is embodied as a longitudinal blade24, whereby distributed over the length of the cutting edge 25 of theblade is a plurality of nozzles 19 for cooling the longitudinal blade24. Similar to the embodiment described in conjunction with FIG. 2, alsowith this embodiment, although not illustrated, a slotted nozzle thatextends over the length of the cutting edge 25 of the longitudinal blade24 can be provided for applying the cooling medium to the cutter blade.

Finally, a further embodiment of the invention is illustrated in FIG. 7,according to which a nozzle 19 is oriented radially relative to thecutting edge of the blade, so that cooling medium that is conveyedthrough the nozzle 19 flows against the cutting edge of the blade in theplane of the cutter blade. With this embodiment, a housing thatsurrounds the cutter blade 14 is also shown and is provided with avacuum device 36 in order to draw off the cooled atmosphere that isproduced about the cutter blade.

There are no limitations with regard to the use of cooling medium; forexample, it would be possible to use an inert cooling gas, liquidnitrogen, liquid carbon dioxide, or even cooled air, and to convey themto the longitudinal cutting machine. Where air cooling is used, it wouldalso be possible to first cool the air to the low temperature that isrequired in the region of the longitudinal cutting machine by providingexpansion nozzles. With all of the cooling media, and with thecorresponding control or fine metering of the use of the pertainingcooling medium, one must pay attention that no icing of the cutterblade, and also no formation of condensation water, occurs that wouldadversely disrupt the cutting process or the quality of the product.

The features of the subject matter of these documents disclosed in thepreceding description, the patent claims, the abstract and the drawingcan be important individually as well as in any desired combination withone another for realizing the various embodiments of the invention.

1-25. (canceled)
 26. A longitudinal cutting machine for cutting a sheetof material conveyed through the cutting machine, comprising: a cutterarrangement, which is provided with at least an upper cutter, for saidsheet of material, which is conveyed through said cutter arrangementacross a cutting point formed by said upper cutter); and at least onenozzle for conveying a cooling medium onto a cutter blade of said uppercutter, wherein said at least one nozzle extends or is distributed overa periphery or length of said cutter blade.
 27. A longitudinal cuttingmachine according to claim 26, wherein said cutter blade is a circularcutter blade, and wherein a plurality of nozzles are distributed overthe periphery of said circular cutter blade.
 28. A longitudinal cuttingmachine according to claim 26, wherein said cutter blade is a circularcutter blade, wherein said at least one nozzle is a single annularslotted nozzle, and wherein said nozzle is distributed over theperiphery of said circular cutter blade.
 29. A longitudinal cuttingmachine according to claim 26, wherein said cutter blade is alongitudinal blade having a cutting edge, and wherein a plurality ofspaced-apart nozzles are distributed over the length of said cuttingedge of said longitudinal cutter blade.
 30. A longitudinal cuttingmachine according to claim 26, wherein said cutter blade is alongitudinal blade having a cutting edge, and wherein said at least onenozzle is a single slotted nozzle that extends over the length of saidcutting edge of said longitudinal cutting blade.
 31. A longitudinalcutting machine according to claim 26, wherein said cutter arrangementincludes a lower cutter, and wherein said at least one nozzle forcooling medium conveyed therethrough is directed onto an inner side ofsaid cutter blade that during a shearing cut rests against said lowercutter.
 32. A longitudinal cutting machine according to claim 26,wherein cooling medium is adapted to be supplied to said cutter blade bynozzles disposed on opposite sides of said cutter blade.
 33. Alongitudinal cutting machine according to claim 26, wherein at least onenozzle is directed radially relative to a cutting edge of said cutterblade.
 34. A longitudinal cutting machine according to claim 26, whereina plurality of slightly spaced-apart cutter blades are provided, andwherein said at least one nozzle is part of a nozzle arrangementdesigned for supplying cooling medium to said plurality of cutterblades.
 35. A longitudinal cutting machine according to claim 26,wherein one of said at least one nozzle is directed directly againstsaid cutting point.
 36. A longitudinal cutting machine according toclaim 26, wherein a housing is provided that surrounds said uppercutter, including said at least one nozzle that is directed against saidcutter blade of said upper cutter.
 37. A longitudinal cutting machineaccording to claim 36, wherein a vacuum device for cooling medium thatis applied is connected to said housing.
 38. A longitudinal cuttingmachine according to claim 36, wherein a plurality of slightlyspaced-apart cutter blades are provided, and wherein said housing,including an associated nozzle arrangement for said at least one nozzle,surrounds said plurality of said cutter blades.
 39. A longitudinalcutting machine according to claim 26, wherein a temperature sensor isassociated with said cutter blade for detecting a temperature of saidupper cutter.
 40. A longitudinal cutting machine according to claim 26,wherein at least one further nozzle is directed onto said sheet ofmaterial in a region thereof disposed upstream of where said sheet ofmaterial is conveyed across said cutting point.
 41. A longitudinalcutting machine according to claim 26, wherein at least one furthernozzle is directed against a region of an already cut sheet of materialthat is disposed downstream of said cutting point and includes a cutedge in said sheet of material.
 42. A longitudinal cutting machineaccording to claim 26, wherein said cutting arrangement is provided witha lower cutter that is associated with said upper cutter, wherein saidlower cutter is embodied as a lower cutter shaft having cutting edgesdisposed thereon, and wherein said lower cutter shaft is designed forconveying said cooling medium therethrough.
 43. A longitudinal cuttingmachine according to claim 26, wherein said cutter arrangement isdesigned for operating in a crimping cut mode, wherein said upper cutteroperates against a shaft, and wherein said shaft is designed forconveying said cooling medium therethrough.
 44. The use of thelongitudinal cutting machine of claim 26 for a temperature sensitivematerial, including the step of: conveying said cooling medium throughsaid at least one nozzle and onto said cutter blade to prevent atemperature of said cutter blade from exceeding a prescribed temperatureduring a cutting operation of said longitudinal cutting machine.
 45. Theuse of the longitudinal cutting machine according to claim 44, whereinsaid step of conveying cooling medium comprises conveying cooling air,an inert cooling gas, liquid nitrogen, or liquid carbon dioxide.
 46. Theuse of the longitudinal cutting machine according to claim 44, whereinsaid cooling medium is conveyed continuously or at periodic intervalsthrough said at least one nozzle.
 47. The use of a longitudinal cuttingmachine for cutting a sheet of temperature sensitive material conveyedthrough the cutting machine, wherein said cutting machine comprises acutter arrangement, which is provided with at least an upper cutter, andoptionally a lower cutter, for said sheet of material, which is conveyedthrough said cutter arrangement across a cutting point formed by saidupper cutter, and wherein said cutting machine has an electrical coolingmeans for cooling at least one of said upper cutter and said lowercutter, including the step of: cooling with said electrical coolingmeans to prevent a temperature of a cutter blade of said cutter fromexceeding a prescribed temperature during a cutting operation of saidlongitudinal cutting machine.